[Devel] [PATCH RHEL7 COMMIT] venet: ipX_forward headroom check: uninit var fixup

[Konstantin Khorenko]

This a fixup for:

[PATCH RHEL7 COMMIT] venet: ipX_forward headroom check

--
Best regards,

Konstantin Khorenko,
Virtuozzo Linux Kernel Team

On 07/17/2017 07:01 PM, Konstantin Khorenko wrote:
> The commit is pushed to "branch-rh7-3.10.0-514.26.1.vz7.33.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
> after rh7-3.10.0-514.26.1.vz7.33.9
> ------>
> commit 5ea4c9af81f7f85437de6b17849607991633fffe
> Author: Konstantin Khorenko <khorenko at virtuozzo.com>
> Date:   Mon Jul 17 19:56:39 2017 +0400
>
>     venet: ipX_forward headroom check: uninit var fixup
>
>     Fixing possible uninitialized variable usage:
>
>     net/ipv4/ip_forward.c: In function 'ip_forward':
>     net/ipv4/ip_forward.c:156:37: error: 'iph' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>      skb->priority = rt_tos2priority(iph->tos);
>                                        ^
>     Fixes: 9a05b36 ("venet: ipX_forward headroom check")
>
>     https://jira.sw.ru/browse/PSBM-68362
>
>     Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
> ---
>  net/ipv4/ip_forward.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
> index 556792c..3a1c2ff 100644
> --- a/net/ipv4/ip_forward.c
> +++ b/net/ipv4/ip_forward.c
> @@ -132,8 +132,10 @@ int ip_forward(struct sk_buff *skb)
>  	    (rt->rt_flags & RTCF_NAT) == 0 &&	  /* no NAT mangling expected */
>  #endif						  /* and */
>  	    (skb->dev->features & NETIF_F_VENET) && /* src is VENET device and */
> -	    (skb_headroom(skb) >= hroom))	 /* skb has enough headroom */
> +	    (skb_headroom(skb) >= hroom)) {	  /* skb has enough headroom */
> +		iph = ip_hdr(skb);
>  		goto no_ttl_decr;
> +	}
>
>  	/* We are about to mangle packet. Copy it! */
>  	if (skb_cow(skb, hroom))
> .
>